2005 Kia Spectra 5 Erratic Idle/RPMs Problems.

[S2500Dog]

Hello everyone,

I have a 2005 Kia Spectra 5 automatic hatchback that been suffering from erratic idle/rpms problems recently. The problem started a little over a month ago when I performed a tune up/ maintenance service on the car consisting of the following items: new NGK laser platinum spark plugs as specified, new NGK wires set, cleaned air filter box, clean throttle body and idle air control valve, cleaned PCV valve, cleaned battery cables and installed new interstate battery specified for this car, added fuel system cleaner to gas tank and did seafoam thru the vacuum lines to complete fuel system/intake cleaning. The original spark plugs were Champion double platinum and the wires set were OEM Hyundai/Kia wires.

The following erratic idle/rpms problems im experiencing are the following:

1. Idle rev itself up to 1200-1500 rpms for one to two mintute at operating temps without touching throttle or pedals.

2. Idle spike up and down throughout times in various rpm ranges when cruising, stopped at intersection, driveway, etc.

3. Car jerks for a moment when accelerating from a stop with idle/rpms acting erratically.

4. Idle/RPMS will vary from 700-800 to over 5000 without touching throttle or pedals especially when the car is in gear.

The plugs and wires are new and installed correctly to specifications; all other services and maintenance were done correctly so Im thinking that the problems could be the idle air control valve or throttle position sensor but Im not exactly sure. If anyone can offer some help and advice with resolving these issues, I would greatly appreciate it. Thank you guys!

 

[Warstud]

If you still have the old Champion Plugs I would put them back in to rule that out.

 

[KrisZ]

Spark plugs do not control idle speed or big amounts of RPM changes. They at most will cause stumbles and RPM drops, not increases. But the idle control valve can do these things and OP obviously touched it. I would start from that.

 

[cptbarkey]

Possible dirty/defect idle air control valve, its common on the beta 2. You may also have a cracked vacuum leak when you took it off to seafoam it.

 

[Kamele0N]

Cracked vacuum hose...check throttle again...and all sensors around it!

On throttle body...just behind throttle itself there is one hole with some small fin wich controls amount of extra fuel during accerlation of engine...check that fin if it is dirty...

 

[Warstud]

Originally Posted By: KrisZ
Spark plugs do not control idle speed or big amounts of RPM changes. They at most will cause stumbles and RPM drops, not increases.

Your right...I responded without reading everything. I agree with whomever said it was a vacuum leak.

 

[147_Grain]

What about the TPS - Throttle Position Sensor?

 

[S2500Dog]

Thank you guys for all the help and advice. I will have my mechanic checkout the throttle position sensor and idle air control valve while performing his diagnostics. I'm confident one of the two items is causing all these strange idle/rpms problems recently. I will keep you guys updated on the results.